Abstract: A method for preparing a meta-(chiral allyl)-substituted pyridine compound includes: S1, in a glove box filled with nitrogen, adding a boron catalyst, a solvent, pinacol borane, and pyridine to a reaction flask and reacting the mixture under stirring at room temperature to 120° C. for 1-12 hours to obtain dihydropyridine; S2, adding a metal catalyst and a chiral ligand to the reaction flask, stirring the mixture, then adding an alkali and allyl ester, and reacting the mixture at ?10° C. to 60° C. for 12-24 hours to obtain a meta-(chiral allyl)-substituted dihydropyridine; and S3, placing the reaction flask in air, reacting the mixture under stirring at room temperature for 1 minute to 12 hours, then performing distillation under reduced pressure to remove the solvent and separation by column chromatography to obtain the meta-(chiral allyl)-substituted pyridine compound.

Abstract: Disclosed are a display apparatus and a device control method.

Abstract: Disclosed are a display apparatus and a method therefor. The method includes: controlling a Bluetooth communication module of the display apparatus to perform device scanning, and displaying scanned devices on a display of the display apparatus; in response to a pairing request triggered for a target device among the scanned devices, establishing a Bluetooth connection based on an A2DP protocol with the target device; obtaining a UUID of the target device; after successfully establishing the Bluetooth connection based on the A2DP protocol, adding the target device to a list of connected devices; determining, based on the UUID, that the target device supports a LE Audio protocol, adding a preset visual indicator for the target device; where the preset visual indicator is used to prompt a user that the Bluetooth connection with the target device is allowed to be switched to a Bluetooth connection based on the LE Audio protocol.

Abstract: A method for preparing a meta-functionalized pyridine compound is provided. The method has a first step, S1, for preparation of 1,4-dihydropyridine, involving: in a glove box filled with nitrogen, adding a catalyst, a solvent, pinacolborane and pyridine to a reaction flask in order and stirring the mixture at 40-110° C. for a reaction for 5-12 hours to obtain 1,4-dihydropyridine. In a second step, S2, catalyzed functionalization of pyridine at the meta-position is provided by adding an imine, an aldehyde, a ketone or a halogenation reagent to the above reaction flask, and stirring the mixture in a nitrogen atmosphere until the reaction is completed; and performing distillation under reduced pressure to remove the solvent and column chromatography separation to obtain a meta-functionalized pyridine, wherein the reaction temperature is 40-110° C., and the reaction time is 5-24 hours.

Abstract: An online system updates the labels on negative examples to account for the possibility that the example is a false negative. The system generates a set of initial training examples that each include a query input by the user and item data for an item presented as a result to the user's query. Each training example also includes an initial label, which represents whether the user interacted with the item presented as a search result. The online system updates the initial label for a negative training example by identifying a set of bridge queries and computing a similarity score between the query for the training example and the bridge queries. The online system computes an updated label for the negative example based on the similarity scores and updates the training example with the updated label.

Abstract: This application relates to the field of artificial intelligence technologies, and provide a knuckle operation identification method and an electronic device. According to this application, when a knuckle performs an operation on different touch regions of a touch panel, an acceleration signal may have different change trends. A touch feature is extracted from a touch signal for determining a contact area and a contact location, and an acceleration feature is extracted from the acceleration signal for determining a magnitude of a touch on a screen. A capacitor binary classification model is used at the front, to extract a confidence score indicating a correlation to a knuckle from a capacitor signal. Then, feature fusion is performed on the acceleration feature, the confidence score, and the touch feature, and a fused feature is input into a knuckle classification model, to obtain a better classification effect.

Abstract: In implementations of systems and procedures for item condition verification, a computing device implements an item condition verification system to compare a marketed condition of an item from an item listing with a delivered condition of the item using one or more machine learning models. Based on the comparison, the item condition verification system outputs a result indicating whether the item is significantly not as described by the item listing.

Abstract: This application relates to the field of artificial intelligence technologies, and provide a knuckle operation identification method and an electronic device. According to this application, when a knuckle performs an operation on different touch regions of a touch panel, an acceleration signal may have different change trends. A touch feature is extracted from a touch signal for determining a contact area and a contact location, and an acceleration feature is extracted from the acceleration signal for determining a magnitude of a touch on a screen. A capacitor binary classification model is used at the front, to extract a confidence score indicating a correlation to a knuckle from a capacitor signal. Then, feature fusion is performed on the acceleration feature, the confidence score, and the touch feature, and a fused feature is input into a knuckle classification model, to obtain a better classification effect.

Abstract: An online system updates the labels on negative examples to account for the possibility that the example is a false negative. The system generates a set of initial training examples that each include a query input by the user and item data for an item presented as a result to the user's query. Each training example also includes an initial label, which represents whether the user interacted with the item presented as a search result. The online system updates the initial label for a negative training example by identifying a set of bridge queries and computing a similarity score between the query for the training example and the bridge queries. The online system computes an updated label for the negative example based on the similarity scores and updates the training example with the updated label.

Abstract: This invention discloses a method for comprehensively apportioning the source contribution to fine particular matter (PM2.5) based on the receptor model and the chemical transport model, which comprises the receptor model calculation steps, chemical transport model calculation steps and comprehensive source apportionment steps; the said comprehensive source apportionment step comprises the following sub-steps: according to the principle of inverse proportionality between uncertainty and weight coefficient, the first (receptor model) uncertainty and the second (chemical transport model) uncertainty are normalized to obtain their respective weight coefficients; the comprehensive source apportionment results are calculated based on the apportionment results of the receptor model and the chemical transport model, and their respective weight coefficient.

Abstract: A treatment agent for an electronic-grade low-dielectric fiberglass cloth, and a preparation method thereof are provided. The treatment agent for an electronic-grade low-dielectric fiberglass cloth is prepared from the following raw materials in weight percentages: a coupling agent A: 0.6% to 1.2%, a coupling agent B: 0.3% to 0.8%, a coupling agent additive: 0.01% to 1.5%, an alcohol: 0.1% to 0.5%, an acid: 0.1% to 0.5%, and water: the balance, where the coupling agent A is a vinyl-containing coupling agent; the coupling agent B is a vinylbenzyl-containing coupling agent; and the coupling agent additive is a salt of a maleic anhydride (MA)-grafted copolymer. On the basis of meeting the low dielectric performance, the treatment agent of the present disclosure improves the binding performance of the low-dielectric fiberglass cloth to a low-dielectric customer resin and enhances the mechanical performance and heat resistance of the low-dielectric fiberglass cloth.

Abstract: Provided is a method for determining a respiratory phase, applied to a ventilation therapy device including a respiratory conduit. The method includes: acquiring a gas flow value of the respiratory conduit, and acquiring a pressure value of a pressure sensor, wherein the pressure sensor is used for collecting a pressure in the respiratory conduit; converting the gas flow value and the pressure value into a first value and a second value under a same reference; and determining a current respiratory phase of a patient based on a difference of the first value and the second value.

Abstract: A gesture-based display interface control method and apparatus, a device and a storage medium, belonging to the technical field of intelligent devices. The method includes: acquiring a first gesture of a user, and determining whether the first gesture is kept for more than a preset time; if the first gesture is kept for more than the preset time, displaying a target virtual gesture point on the current display interface; and acquiring a second gesture of the user, and moving the target virtual gesture point on the current display interface according to the second gesture. According to the method, the virtual gesture point is displayed on the display interface, and the virtual gesture point is randomly moved on the display interface, so that any interactive control on the current display interface can be operated, and gesture control is more intelligent and comprehensive while improving the accuracy of gesture control.

Abstract: The subject matter includes a smart device control method, comprising: receiving a device control instruction, and acquiring device distance information respectively between the first positioning device and each smart device, and between the second positioning device and each smart device: calculating a LOS deviation angle between a wearer of the head-mounted device and each of the smart devices based on the device distance information, wherein the LOS deviation angle is an angle between the wearer's direct LOS and a relative direction of the device, and the relative direction of the device is a direction of a line connecting a midpoint of a connection between the first positioning device and the second positioning device to the smart devices: and determining a smart device with a LOS deviation angle less than a pre-set value as a to-be-controlled device, and sending a device control instruction to the to-be-controlled device.

Abstract: Provided are a bone conduction-based eating monitoring method and apparatus, a terminal device, and a storage medium, the method including monitoring, by means of smart glasses, a chewing behavior for food being eaten to obtain a vibration signal of skull related to the chewing behavior; counting the number of chews according to the vibration signal to obtain the number of consecutive chews; and if the number of consecutive chews does not reach a target number of chews and the chewing behavior of a user terminates, sending first prompt information; if the number of consecutive chews reaches the target number of chews, sending second prompt information.

Abstract: A treatment agent for an electronic-grade low-dielectric fiberglass cloth, and a preparation method thereof are provided. The treatment agent for an electronic-grade low-dielectric fiberglass cloth is prepared from the following raw materials in weight percentages: a coupling agent A: 0.6% to 1.2%, a coupling agent B: 0.3% to 0.8%, a coupling agent additive: 0.01% to 1.5%, an alcohol: 0.1% to 0.5%, an acid: 0.1% to 0.5%, and water: the balance, where the coupling agent A is a vinyl-containing coupling agent; the coupling agent B is a vinylbenzyl-containing coupling agent; and the coupling agent additive is a salt of a maleic anhydride (MA)-grafted copolymer. On the basis of meeting the low dielectric performance, the treatment agent of the present disclosure improves the binding performance of the low-dielectric fiberglass cloth to a low-dielectric customer resin and enhances the mechanical performance and heat resistance of the low-dielectric fiberglass cloth.

Abstract: Disclosed is a control method for an audio device, the audio device includes a playing component and a display screen rotatably connected to the playing component, and the control method for the audio device includes the following steps: detecting a position of a user; determining a rotation mode of the display screen according to the position; acquiring a display expression corresponding to the rotation mode; and displaying the display expression on the display screen, and controlling the display screen to operate according to the rotation mode. This disclosure further provides an audio device and a computer-readable storage medium. This application improves the user's interaction experience with the audio device.

Abstract: Disclosed is a control method for an audio device, the audio device includes a wireless charging module and a display screen, and the control method for the audio device includes the following steps: in response to detecting a mobile device is placed on the audio device, acquiring a screen placement state of the mobile device, the screen placement state includes at least one of a screen flat state, a screen horizontal state and a screen vertical state; and displaying display content of the display screen on a screen of the mobile device according to the screen placement state. This disclosure further provides an audio device and a computer-readable storage medium. The problem that the display effect of the display screen of the audio device will be affected when the audio device performs wireless charging for the mobile device has been solved.

Abstract: A gesture-based display interface control method and apparatus, a device and a storage medium, belonging to the technical field of intelligent devices. The method includes: acquiring a first gesture of a user, and determining whether the first gesture is kept for more than a preset time; if the first gesture is kept for more than the preset time, displaying a target virtual gesture point on the current display interface; and acquiring a second gesture of the user, and moving the target virtual gesture point on the current display interface according to the second gesture. According to the method, the virtual gesture point is displayed on the display interface, and the virtual gesture point is randomly moved on the display interface, so that any interactive control on the current display interface can be operated, and gesture control is more intelligent and comprehensive while improving the accuracy of gesture control.

Abstract: A method for preparing a pyridine compound substituted with trifluoromethylthio, difluoromethylthio or trifluoromethyl in the meta position is provided, which includes S1. in a glove box filled with nitrogen, adding a catalyst, a solvent, pinacolborane, and pyridine to a reaction flask, stirring the mixture, and performing a reaction at 40-100° C. for 2-12 hours to obtain dihydropyridine; S2. adding a trifluoromethylthio reagent, a difluoromethylthio reagent, or a trifluoromethyl reagent to the reaction flask, stirring the mixture, and performing a reaction at room temperature to 80° C. for 2-12 hours to obtain trifluoromethylthio-, difluoromethylthio- or trifluoromethyl-substituted dihydropyridine; and S3.